Quote from kip:
I don't know why I'm still trying when I have no intention of doing a 21% (since it's not the real lowest).
I'm not 100% up to date with it, but AFAIK sw grapple skip currently requires floating, so this way is almost certainly better no matter how hard it is.
In fact if this works IIRC we're down to only a single skip now (emerald) that needs a SW float, and it may be possible to refine that skip. This is all speaking from a sw-skips-are-legal point of view, of course. Skipping grapple would mean that 21% could make it onto the SDA if someone was prepared to run it (not me this time.)
<EDIT>got it now, basically by watching the video more closely. I was under the impression that any instant unmorph would do, but it seems the position you roll off at and the precise time at which you unmorph do make a difference for some weird reason.
For me holding L seems to give a lot more distance, I couldn't make it without, but that might just have been randomness. I still have better consistency with the dash though.</EDIT>